To effectively use mobile communication network resources, the third Generation mobile communication global standardization organization (3GPP) Release 6 puts forward the MBMS of mobile communication networks, and thus in the mobile communication networks a point-to-multipoint service is provided in which one data source sends data to multiple users, thereby realizing network resources share, and improving the utilization ratio of the network resources, especially the sharing of air interface resources.
The MBMS put forward by the 3GPP can realize not only multicast and broadcast of plain text low rate messages, but also multicast and broadcast of high rate multimedia services, which doubtlessly complies with the trend in future mobile data development. To further improve the transmission rate of MBMS data, for the FDD (Frequency Division Duplex) and the 3.84 Mcps TDD (Time Division Duplex), the 3GPP is currently putting forward a solution of using a dedicated independent carrier to bear the MBMS, that is, in the coverage area of a current universal mobile communication system a frequency layer dedicated for transmitting the MBMS is additionally established, and user equipments are capable of receiving an ordinary carrier and a dedicated carrier to transmit the MBMS.
In the 3GPP Release 7, the IPWireless puts forward a new frame structure (a burst type) for the 3.84 Mcps TDD to support a MBMS dedicated carrier system. To meet operators' requirements on coverage and transmission rate, the current frame structure is optimized. FIG. 1 is a schematic view of the frame structure of a MBMS dedicated carrier in a TDD system, and as shown in FIG. 1, the MBMS dedicated carrier wireless frame is 10 ms, and each frame includes two sub-frames with the same structure being 5 ms respectively. The sub-frame includes 7 service time slots and one control time slot, the service time slots are TS0 to TS6 from the left to the right sequentially, and the control time slot is located between TS0 and TS1. To meet requirements on the transmission of data services, the time slots in the sub-frame are all downlink time slots.
FIG. 2 is a schematic view of the time slot structure in the frame structure in FIG. 1, and as shown in FIG. 2, despite the service time slot or the control time slot, the head of the time slot is a 112-chip preamble consisting of a 64-chip channel estimation code and a 48-chip cyclic protection interval. The cyclic protection may also contain 32 chips, the preamble may also contain 96 chips, and the structure of the preamble is not separately illustrated with a figure herein.
Currently, new MBMS dedicated carrier systems overlap the coverage of current TD-SCDMA systems, and there exists frequency isolation between them, no interference will occur between them, and handset user equipments can not only receive broadcast television programs, but also achieve ordinary voice services. However, mobile television terminals can only receive broadcast television programs. It is very important for handset user equipments and mobile television terminals accessing and synchronizing to the MBMS dedicated carrier system, which is a precondition for users to enjoy MBMS services, and currently there is no any related solution.